湘黔桂交界区富禄组与富禄间冰期的再划分     

林树基  肖加飞  卢定彪  刘爱民  牟世勇  陈仁  易成兴  王兴理 《地质通报》2010,29(2)

在中国南华系层型剖面优选区之一--湘黔桂交界区,富禄闻冰期可再分为3个相对较暖热的气候阶段(间冰段)和2个相对寒冷的气候阶段(冰段),即(自老而新):三江间冰段、龙家冰段、烂阳闻冰段、两界河冰段、大塘坡间冰段.相应地,富禄间冰期沉积地层--富禄组可分5个段,即:三江段、龙家段、烂阳段、两界河段、大塘坡段.另外.对古城组和铁丝坳组层型的湖北长阳古城剖面、贵州松桃大塘坡剖面和相关资料的再研究揭示,"古城组"和"铁丝坳组"都是富禄间冰期晚冰段(即两界河冰段)的沉积,均不宜替代长安组作为南华纪早冰期沉积的代表.  相似文献   

西藏措勤曲洛地区新发现侏罗纪地层     

赵兵  刘登忠  陶晓风  马润则  胡新伟  王辉 《地质通报》2010,29(11):1633-1639

在西藏措勤县曲洛乡门缸错地区发现了侏罗纪地层,详细描述了实测的侏罗系剖面,将该套地层暂时命名为曲洛组。讨论了该组的岩石组合特征和沉积环境,认为主要为一套海陆过渡三角洲—滨岸泻湖相沉积。根据曲洛组中的双壳化石、古植物及孢粉组合特征将这套地层的时代确定为早侏罗世。措勤地区下侏罗统的发现为区域地质构造演化研究和矿产资源勘查提供了新资料。  相似文献   

山西王家岭矿区奥陶系碳酸盐岩溶蚀规律研究   总被引：2，自引：0，他引：2  

桂辉  许进鹏 《中国煤炭地质》2010,(1):46-49

为研究王家岭矿区奥陶系碳酸盐岩的溶蚀规律,模拟造成差异性溶蚀的主要因素进行了实验。在常温常压、溶蚀液碳酸水的pH值为6.5～6.9、每次溶蚀时间控制在24h左右的条件下,对矿区不同层段的碳酸盐岩进行溶蚀实验。实验发现,碳酸盐岩的成分和结构是影响溶蚀指标的重要因素,比溶蚀度和比溶解度总体趋势是白云岩灰岩膏岩;不溶物含量的增大使比溶蚀度和比溶解度下降,机械破坏量呈非线性增加;相同情况下方解石溶解速度快于白云石2～3倍。该实验结果为矿区进行水文地质研究提供了基础数据。  相似文献   

Molecular characterization of dissolved organic matter (DOM) along a river to ocean transect of the lower Chesapeake Bay by ultrahigh resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry   总被引：1，自引：0，他引：1  

Rachel L. Sleighter  Patrick G. Hatcher   《Marine Chemistry》2008,110(3-4):140-152

In this study, electrospray ionization coupled to Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS) is utilized to molecularly characterize DOM as it is transported along a river to estuary to ocean transect of the lower Chesapeake Bay system. The ultrahigh resolving power (greater than 500,000) and mass accuracy of FTICR-MS allow for the resolution of the thousands of components in a single DOM sample, and can therefore elucidate the molecular-level changes that occur during DOM transformation from a terrestrial location to the marine environment. An important feature of FTICR-MS is that its sensitivity allows for direct analysis of low salinity samples without employing the traditional concentration approaches involving C₁₈ extraction or ultrafiltration. To evaluate the advantages of using direct analysis, a C₁₈ extract of riverine water is compared to its whole, unfractionated water, and it was determined that the C₁₈ extraction is selective in that it eliminates two major series of compounds. One group is aliphatic amines/amides that are not adsorbed to the C₁₈ disk because they exist as positive ions prior to extraction. The second group is tannin-like compounds with higher oxygen contents and a more polar quality that also allow them not to be adsorbed to the C₁₈ disk. This direct approach could not be used for brackish/saline waters, so the C₁₈ method is resorted to for those samples. Along the subject transect, a significant difference is observed in the molecular composition of DOM, as determined from assigned molecular formulas. The DOM tends to become more aliphatic and contain lower abundances of oxygen-rich molecules as one progresses from inshore to the offshore. A considerable amount of molecular formula overlap does exist between samples from sites along the transect. This can be explained as either the presence of refractory material that persists throughout the transect, due to its resistance to degradation, or that the assigned molecular formulas are the same but the chemical structures are different. ESI-FTICR-MS is a powerful technique for the investigation of DOM and has the ability to detect compositional variations along the river to ocean transect. Visualization tools such as two dimensional and three dimensional van Krevelen diagrams greatly assist in highlighting the shift from the more aromatic, terrestrial DOM to the more aliphatic, marine DOM.  相似文献   

基于空间分析方法的疾病地理研究进展     

郭凤云  路紫 《测绘软科学研究》2009,(6):22-26

健康已成为人类普遍关注的问题，以人类健康为研究对象的医学地理目前正成为全球性的研究热点，其中疾病地理又是相对成熟的分支和主要的研究方向。空间分析方法的引入，开拓了疾病地理研究的新领域，也成为疾病监测和评估的一个辅助工具，这使得疾病时空研究取得了重大进展。本文在前人研究的基础上，从时空两方面揭示了疾病地理近年来主要的研究动态和特点，并提出了当前疾病地理研究的某些不足，最后展望了今后我国疾病地理的研究任务和方向。  相似文献   

吉林市现代地籍管理信息系统的开发与应用     

张寿东张树楠  费新宇郝辉 《地理信息世界》2005,3(B08):55-59

数字地籍是地籍发展的重要趋势。地籍管理信息系统是数字地籍建设的核心，文章在分析目前我国地籍信息系统建设现状的基础上，指出以后地籍管理信息系统将是面向网络的、以空间数据库为核心的、集成应用的系统。文章重点介绍基于大型组件式GIS平台SuperMap GIS所开发的吉林市地籍管理信息系统的软件组织、系统结构、系统特色以及系统应用模式，从而提出基于面向网络一体化地籍管理信息系统的建设思路，为我国数字地籍的建设提供参考。  相似文献   

地球空间元数据的使用研究   总被引：14，自引：0，他引：14  

李军 《地球信息科学学报》2000,2(3):8-13

近年来,地球空间数据获取手段的拓宽使其数据量激增。从空间海量数据中快速获取目标数据,必须依赖于元数据。  相似文献   

Design for Vibrator Field Experiment Based- on Vibrator- earth System     

Chen Zubin  Lin Jun  Liang Tiecheng  Zhang Linhang 《世界地质(英文版)》2000,3(1)

  相似文献   

健全测绘管理机构　发展我国测绘事业     

张楚垣 《地理信息世界》2000,(3)

省级测绘管理机构改革是目前测绘机构改革的热门话题，但管理机构的模式尚无定论，根据测绘管理机构的法定职能及未来测绘事业发展的需要，提出测绘管理机构拥有行政管理职能的法律依据，测绘管理机构的职能设置方案，及加强各级测绘管理机构的行政管理职能对测绘事业发展的重要意义。  相似文献   

The contribution of small grains to the opacity of protoplanetary atmospheres     

M Podolak 《Icarus》2003,165(2):428-437

I compute the opacity of grains in a protoplanetary atmosphere. The grain size distribution at different levels in the atmosphere is calculated using a simple microphysical model of grain growth via collisions and destruction via vaporization at high temperatures. The Rosseland mean opacity of the resulting distribution is then computed. For most cases examined, the grain opacity is significantly lower than earlier estimates.  相似文献